The weapons police say were used by suspects in last week’s mass killings were reportedly purchased legally despite the state’s strict gun laws. SAN BERNARDINO COUNTY SHERIFF'SSan Bernardino County Sheriff's Department

The weapons police say were used by suspects in last week’s mass killings were reportedly purchased legally despite the state’s strict gun laws. SAN BERNARDINO COUNTY SHERIFF'SSan Bernardino County Sheriff's Department

California lawmakers have acted repeatedly to give the state what are considered the nation’s strictest gun laws.

So, how was it that guns obtained here legally came to be used in the worst terror attack on domestic soil since Sept. 11?

In the days following the events in San Bernardino, in which 14 people were killed and 21 injured, state elected officials have advocated for stronger local and federal laws. And the massacre, carried out by a married couple and branded an “act of terrorism” by President Barack Obama, is forcing state officials to once again confront questions about how, for all its firm statutes, assault-style rifles have been able to proliferate.

“California always prides itself on its leadership, and we have done some heroic things on gun safety in the past,” Lt. Gov. Gavin Newsom said. “But the bar is not as high as it should be.”

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California became the first state to prohibit semiautomatic rifles after five children were gunned down by a man with a semi-automatic AK-47 in the 1989 shooting at Cleveland Elementary School in Stockton.

Over time, the state came to ban three major categories of assault weapons: those specified by name such as the Colt AR-15; the AK and AR-15 series; and semi-automatic rifles with the capacity to accept a detachable magazine and features such as a pistol grip or telescoping stock. Also banned are semi-automatic rifles with fixed magazines in excess of 10 rounds and semi-automatic, center-fire rifles with overall lengths of less than 30 inches.

There remains a loophole in regulation, however, allowing people to modify their guns to make them even more powerful.

Ari Freilich of the Law Center to Prevent Gun Violence said gun manufacturers have introduced “California-compliant” assault weapons. In many cases, there is only one difference between those firearms and what are legally considered assault weapons: Instead of using a finger to easily detach and reload the magazine, one must use a bullet to press a button to do so. Under the regulations interpreting the law, California’s Justice Department does not consider it an assault weapon if it requires a tool to remove the magazine, Freilich said. “And a bullet is unfortunately considered a ‘tool’ due to that loophole.”

“These are essentially assault weapons,” he said. “It is clearly the spirit and intent of California’s leadership to remove military-grade weaponry that can fire at such a high capacity and can be reloaded so quickly that really its only purpose is to inflict mass carnage in as short a time as possible.”

In 2013, Gov. Jerry Brown vetoed a measure, Senate Bill 374, that would have closed the loophole by treating semi-automatic rifles that accept a detachable magazine as assault weapons. A separate effort died before getting to his desk.

The weapons used by Syed Rizwan Farook and Tashfeen Malik – two pistols and two rifles – were obtained legally in California. FBI officials said the pistols were bought by Farook, purchases that would have triggered a background check. The assault-style rifles were originally bought by Enrique Marquez and then illegally modified. Under California law, transfers in ownership must go through a licensed dealer pursuant to a background check. A former neighbor of Farook, Marquez was questioned by investigators, but they were not prepared to discuss him as a possible suspect.

Officials have said that one of the .223-caliber semi-automatic rifles was altered to essentially function like an automatic weapon, while the other was changed to accommodate a high-capacity, 30-round magazine prohibited in California.

Newsom said that briefings he has received suggest it is too early to pass judgment about the cache of weapons and ammunition and whether a particular law, or the various laws being contemplated, would apply. He is proposing a gun-control measure for next year’s ballot and said now is not the time to hold back in passing more “common sense” measures.

“To the extent it would address the issues of San Bernardino, perhaps not,” Newsom said. “But would it have impacted (other) mass shootings in California? That’s an open-ended question for consideration.

“I am absolutely convinced that the laws on the books have saved lives, and I am equally convinced that by doing what we are attempting to do with this initiative, we will be able to save lives in the future,” Newsom said.

California’s distinction as having the strongest firearms laws, awarded by a gun-control advocacy organization formed after a 1993 mass shooting in San Francisco, is based on a handful of requirements in state law. In addition to the assault weapons law, anyone purchasing a gun must submit to a background check, go through a state-licensed dealer and obtain a safety certificate after passing a written exam. The state also imposes a 10-day waiting period for firearms and bans most large-capacity ammunition magazines.

The sustained gun-control push is unfolding amid a stalemate in Washington. Last week, the U.S. Senate rejected a pair of Democratic-backed measures to ban people on the terror watch list from buying guns, as well as make it tougher for those with felony offenses and mental illnesses.

But even in California, which last year became the first state to enact a gun-violence restraining order, there has been healthy resistance to more gun laws.

Craig DeLuz, a spokesman for the Firearms Policy Coalition, said SB 374, the assault weapons measure by then-Senate President Pro Tem Darrell Steinberg, was an illustration of lawmakers overreaching because they don’t understand the technology.

DeLuz said when a firearm jams, for example, and a round is trapped in the chamber, it creates a potentially dangerous situation. He said one of the things a gun owner can do is remove the magazine to take out the additional unexploded rounds. Currently, they could use the “bullet button” to detach the magazine.

“If the only way to remove the magazine is to have to open up the action, you risk having the round explode in your face,” DeLuz said.

They don’t understand the technology.

Craig DeLuz, spokesman for the Firearms Policy Coalition

In his veto message for SB 374, Brown said California already has some of the strictest gun laws in the country. The measure also sought to require those with semi-automatic guns with detachable magazines to register them.

Brown said the ban would cover low-capacity rifles commonly used for hunting, firearms training and marksmanship practice, as well as some historical and collectible firearms. “I don’t believe that this bill’s blanket ban on semi-automatic rifles would reduce criminal activity or enhance public safety enough to warrant this infringement on gun owners’ rights,” he wrote.

In Paris for a conference on climate change, Brown expressed hesitation about Newsom’s statewide ballot measure in urging Congress to “get off their partisan seat and do something to protect the American people.”

“We have among the strictest gun control regulations in the country, and it doesn’t do us that much good if other states and the federal government is basically passive in this effort to keep guns out of the wrong hands,” he said Monday on CNN.

Meanwhile, other state leaders are drafting proposals. Senate President Pro Tem Kevin de León, D-Los Angeles, the author of several past gun control measures, is promising a package of bills when the Legislature returns from recess next month. One measure expected to be introduced in the Assembly would bar people on the government’s no-fly list from being able to purchase guns and certain chemicals.

Newsom has joined the law center in introducing his gun control measure for next year’s ballot with a provision requiring ammunition buyers to undergo background checks. While California bans the importation, manufacture and sale of large-capacity ammunition magazines, Newsom’s measure would prohibit their possession and require anyone who has them to sell to a licensed firearm dealer, transfer them out of state or relinquish them to law enforcement for disposal. It also would establish a process to recover guns from people barred from owning them because of a criminal record and mandate individuals whose guns were lost or stolen to report to law enforcement.

“In an ideal world, we would have national leadership on this: Congress would level the playing field, and as a consequence every state would have to abide by a minimum level of common sense as it relates to gun safety,” Newsom said.

But he said there is still value in California leading on the gun issue, adding, “I don’t want to be a bystander.”